1. 01 Oct, 2014 1 commit
    • David Feuer's avatar
      Use dropWhileEndLE p instead of reverse . dropWhile p . reverse · 2a885688
      David Feuer authored
      Summary: Using `dropWhileEndLE` tends to be faster and easier to read
      than the `reverse . dropWhile p . reverse` idiom. This also cleans up
      some other, nearby, messes. Fix #9616 (incorrect number formatting
      potentially leading to incorrect numbers in output).
      Test Plan: Run validate
      Reviewers: thomie, rwbarton, nomeata, austin
      Reviewed By: nomeata, austin
      Subscribers: simonmar, ezyang, carter, thomie
      Projects: #ghc
      Differential Revision: https://phabricator.haskell.org/D259
      GHC Trac Issues: #9623, #9616
  2. 26 Sep, 2014 1 commit
  3. 25 Jun, 2014 1 commit
  4. 12 Jun, 2014 1 commit
  5. 11 Jun, 2014 2 commits
    • Gabor Greif's avatar
      Some typos in comments · edd57645
      Gabor Greif authored
    • eir@cis.upenn.edu's avatar
      Fix #9062. · e79e2c39
      eir@cis.upenn.edu authored
      Removed (pprEqPred (coercionKind co)) in favor of
      (pprType (coercionType co)).
      Also had to make "~R#" a *symbolic* identifier and BuiltInSyntax
      to squelch prefix notation and module prefixes in output. These
      changes are both sensible independent of #9062.
  6. 06 Jun, 2014 2 commits
  7. 03 Jun, 2014 1 commit
    • Simon Peyton Jones's avatar
      Do pretty-printing of TyThings via IfaceDecl (Trac #7730) · b4856f9f
      Simon Peyton Jones authored
      All the initial work on this was done fy 'archblob' (fcsernik@gmail.com);
      thank you!
      I reviewed the patch, started some tidying, up and then ended up in a huge
      swamp of changes, not all of which I can remember now.  But:
      * To suppress kind arguments when we have -fno-print-explicit-kinds,
          - IfaceTyConApp argument types are in a tagged list IfaceTcArgs
      * To allow overloaded types to be printed with =>, add IfaceDFunTy to IfaceType.
      * When printing data/type family instances for the user, I've made them
        print out an informative RHS, which is a new feature. Thus
              ghci> info T
              data family T a
              data instance T Int = T1 Int Int
              data instance T Bool = T2
      * In implementation terms, pprIfaceDecl has just one "context" argument,
        of type IfaceSyn.ShowSub, which says
             - How to print the binders of the decl
               see note [Printing IfaceDecl binders] in IfaceSyn
             - Which sub-comoponents (eg constructors) to print
      * Moved FastStringEnv from RnEnv to OccName
      It all took a ridiculously long time to do.  But it's done!
  8. 15 May, 2014 1 commit
    • Herbert Valerio Riedel's avatar
      Add LANGUAGE pragmas to compiler/ source files · 23892440
      Herbert Valerio Riedel authored
      In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
      reorganized, while following the convention, to
      - place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
        any `{-# OPTIONS_GHC #-}`-lines.
      - Moreover, if the list of language extensions fit into a single
        `{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
        line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
        individual language extension. In both cases, try to keep the
        enumeration alphabetically ordered.
        (The latter layout is preferable as it's more diff-friendly)
      While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
      occurences by `{-# OPTIONS_GHC ... #-}` pragmas.
  9. 04 Apr, 2014 1 commit
  10. 19 Mar, 2014 1 commit
  11. 13 Mar, 2014 1 commit
  12. 11 Feb, 2014 1 commit
  13. 20 Jan, 2014 1 commit
    • cactus's avatar
      Implement pattern synonyms · 4f8369bf
      cactus authored
      This patch implements Pattern Synonyms (enabled by -XPatternSynonyms),
      allowing y ou to assign names to a pattern and abstract over it.
      The rundown is this:
        * Named patterns are introduced by the new 'pattern' keyword, and can
          be either *unidirectional* or *bidirectional*. A unidirectional
          pattern is, in the simplest sense, simply an 'alias' for a pattern,
          where the LHS may mention variables to occur in the RHS. A
          bidirectional pattern synonym occurs when a pattern may also be used
          in expression context.
        * Unidirectional patterns are declared like thus:
              pattern P x <- x:_
          The synonym 'P' may only occur in a pattern context:
              foo :: [Int] -> Maybe Int
              foo (P x) = Just x
              foo _     = Nothing
        * Bidirectional patterns are declared like thus:
              pattern P x y = [x, y]
          Here, P may not only occur as a pattern, but also as an expression
          when given values for 'x' and 'y', i.e.
              bar :: Int -> [Int]
              bar x = P x 10
        * Patterns can't yet have their own type signatures; signatures are inferred.
        * Pattern synonyms may not be recursive, c.f. type synonyms.
        * Pattern synonyms are also exported/imported using the 'pattern'
          keyword in an import/export decl, i.e.
              module Foo (pattern Bar) where ...
          Note that pattern synonyms share the namespace of constructors, so
          this disambiguation is required as a there may also be a 'Bar'
          type in scope as well as the 'Bar' pattern.
        * The semantics of a pattern synonym differ slightly from a typical
          pattern: when using a synonym, the pattern itself is matched,
          followed by all the arguments. This means that the strictness
          differs slightly:
              pattern P x y <- [x, y]
              f (P True True) = True
              f _             = False
              g [True, True] = True
              g _            = False
          In the example, while `g (False:undefined)` evaluates to False,
          `f (False:undefined)` results in undefined as both `x` and `y`
          arguments are matched to `True`.
      For more information, see the wiki:
          https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms/ImplementationReviewed-by: Simon Peyton Jones's avatarSimon Peyton Jones <simonpj@microsoft.com>
      Signed-off-by: default avatarAustin Seipp <austin@well-typed.com>
  14. 03 Jan, 2014 1 commit
  15. 13 Nov, 2013 1 commit
  16. 01 Oct, 2013 1 commit
  17. 06 Jun, 2013 2 commits
    • Simon Peyton Jones's avatar
    • Simon Peyton Jones's avatar
      Implement cardinality analysis · 99d4e5b4
      Simon Peyton Jones authored
      This major patch implements the cardinality analysis described
      in our paper "Higher order cardinality analysis". It is joint
      work with Ilya Sergey and Dimitrios Vytiniotis.
      The basic is augment the absence-analysis part of the demand
      analyser so that it can tell when something is used
      	 at most once
       	 some other way
      The "at most once" information is used
          a) to enable transformations, and
             in particular to identify one-shot lambdas
          b) to allow updates on thunks to be omitted.
      There are two new flags, mainly there so you can do performance
          -fkill-absence   stops GHC doing absence analysis at all
          -fkill-one-shot  stops GHC spotting one-shot lambdas
                           and single-entry thunks
      The big changes are:
      * The Demand type is substantially refactored.  In particular
        the UseDmd is factored as follows
            data UseDmd
              = UCall Count UseDmd
              | UProd [MaybeUsed]
              | UHead
              | Used
            data MaybeUsed = Abs | Use Count UseDmd
            data Count = One | Many
        Notice that UCall recurses straight to UseDmd, whereas
        UProd goes via MaybeUsed.
        The "Count" embodies the "at most once" or "many" idea.
      * The demand analyser itself was refactored a lot
      * The previously ad-hoc stuff in the occurrence analyser for foldr and
        build goes away entirely.  Before if we had build (\cn -> ...x... )
        then the "\cn" was hackily made one-shot (by spotting 'build' as
        special.  That's essential to allow x to be inlined.  Now the
        occurrence analyser propagates info gotten from 'build's stricness
        signature (so build isn't special); and that strictness sig is
        in turn derived entirely automatically.  Much nicer!
      * The ticky stuff is improved to count single-entry thunks separately.
      One shortcoming is that there is no DEBUG way to spot if an
      allegedly-single-entry thunk is acually entered more than once.  It
      would not be hard to generate a bit of code to check for this, and it
      would be reassuring.  But it's fiddly and I have not done it.
      Despite all this fuss, the performance numbers are rather under-whelming.
      See the paper for more discussion.
             nucleic2          -0.8%    -10.9%      0.10      0.10     +0.0%
               sphere          -0.7%     -1.5%      0.08      0.08     +0.0%
                  Min          -4.7%    -10.9%     -9.3%     -9.3%    -50.0%
                  Max          -0.4%     +0.5%     +2.2%     +2.3%     +7.4%
       Geometric Mean          -0.8%     -0.2%     -1.3%     -1.3%     -1.8%
      I don't quite know how much credence to place in the runtime changes,
      but movement seems generally in the right direction.
  18. 25 Apr, 2013 1 commit
  19. 19 Oct, 2012 1 commit
  20. 16 Oct, 2012 1 commit
    • ian@well-typed.com's avatar
      Some alpha renaming · cd33eefd
      ian@well-typed.com authored
      Mostly d -> g (matching DynFlag -> GeneralFlag).
      Also renamed if* to when*, matching the Haskell if/when names
  21. 09 Oct, 2012 1 commit
  22. 14 Jul, 2012 1 commit
    • Ian Lynagh's avatar
      Add a separate FastZString type · 509d2ad2
      Ian Lynagh authored
      FastStrings are now always UTF8-encoded.
      There's no StringTable for FastZString, but I don't think one is needed.
      We only ever make a FastZString by running zEncodeFS on a FastString,
      and the FastStrings are shared via the FastString StringTable, so we get
      the same FastZString from the IORef.
  23. 21 Jun, 2012 1 commit
    • jpm@cs.ox.ac.uk's avatar
      Allow deriving Generic1 · 156ec95a
      jpm@cs.ox.ac.uk authored
      This completes the support for generic programming introduced
      in GHC 7.2. Generic1 allows defining generic functions that
      operate on type containers, such as `fmap`, for instance.
      Along the way we have fixed #5936 and #5939, allowing
      deriving Generic/Generic1 for data families, and disallowing
      deriving Generic/Generic1 for instantiated types.
      Most of this patch is Nicolas Frisby's work.
  24. 24 Mar, 2012 1 commit
  25. 09 Jan, 2012 1 commit
    • Iavor S. Diatchki's avatar
      Change -XTypeOperators to treat all type-operators as type-constructors. · 85926ae6
      Iavor S. Diatchki authored
      Previously, only type operators starting with ":" were type constructors,
      and writing "+" in a type resulted in a type variable.  Now, type
      variables are always ordinary identifiers, and all operators are treated
      as constructors.  One can still write type variables in infix form though,
      for example, "a `fun` b" is a type expression with 3 type variables: "a",
      "fun", and "b".
      Writing (+) in an import/export list always refers to the value (+)
      and not the type.   To refer to the type one can write either "type (+)",
      or provide an explicit suobrdinate list (e.g., "(+)()").  For clarity,
      one can also combine the two, for example "type (+)(A,B,C)" is also
      accepted and means the same thing as "(+)(A,B,C)" (i.e., export the type
      (+), with the constructors A,B,and C).
  26. 03 Jan, 2012 1 commit
    • Simon Peyton Jones's avatar
      Major refactoring of CoAxioms · 98a642cf
      Simon Peyton Jones authored
      This patch should have no user-visible effect.  It implements a
      significant internal refactoring of the way that FC axioms are
      handled.  The ultimate goal is to put us in a position to implement
      "pattern-matching axioms".  But the changes here are only does
      refactoring; there is no change in functionality.
       * We now treat data/type family instance declarations very,
         very similarly to types class instance declarations:
         - Renamed InstEnv.Instance as InstEnv.ClsInst, for symmetry with
           FamInstEnv.FamInst.  This change does affect the GHC API, but
           for the better I think.
         - Previously, each family type/data instance declaration gave rise
           to a *TyCon*; typechecking a type/data instance decl produced
           that TyCon.  Now, each type/data instance gives rise to
           a *FamInst*, by direct analogy with each class instance
           declaration giving rise to a ClsInst.
         - Just as each ClsInst contains its evidence, a DFunId, so each FamInst
           contains its evidence, a CoAxiom.  See Note [FamInsts and CoAxioms]
           in FamInstEnv.  The CoAxiom is a System-FC thing, and can relate any
           two types, whereas the FamInst relates directly to the Haskell source
           language construct, and always has a function (F tys) on the LHS.
         - Just as a DFunId has its own declaration in an interface file, so now
           do CoAxioms (see IfaceSyn.IfaceAxiom).
         These changes give rise to almost all the refactoring.
       * We used to have a hack whereby a type family instance produced a dummy
         type synonym, thus
            type instance F Int = Bool -> Bool
         translated to
            axiom FInt :: F Int ~ R:FInt
            type R:FInt = Bool -> Bool
         This was always a hack, and now it's gone.  Instead the type instance
         declaration produces a FamInst, whose axiom has kind
            axiom FInt :: F Int ~ Bool -> Bool
         just as you'd expect.
       * Newtypes are done just as before; they generate a CoAxiom. These
         CoAxioms are "implicit" (do not generate an IfaceAxiom declaration),
         unlike the ones coming from family instance declarations.  See
         Note [Implicit axioms] in TyCon
      On the whole the code gets significantly nicer.  There were consequential
      tidy-ups in the vectoriser, but I think I got them right.
  27. 14 Nov, 2011 1 commit
  28. 11 Nov, 2011 1 commit
    • dreixel's avatar
      New kind-polymorphic core · 09015be8
      dreixel authored
      This big patch implements a kind-polymorphic core for GHC. The current
      implementation focuses on making sure that all kind-monomorphic programs still
      work in the new core; it is not yet guaranteed that kind-polymorphic programs
      (using the new -XPolyKinds flag) will work.
      For more information, see http://haskell.org/haskellwiki/GHC/Kinds
  29. 04 Nov, 2011 2 commits
  30. 09 Sep, 2011 2 commits
  31. 06 Sep, 2011 1 commit
    • batterseapower's avatar
      Implement -XConstraintKind · 9729fe7c
      batterseapower authored
      Basically as documented in http://hackage.haskell.org/trac/ghc/wiki/KindFact,
      this patch adds a new kind Constraint such that:
        Show :: * -> Constraint
        (?x::Int) :: Constraint
        (Int ~ a) :: Constraint
      And you can write *any* type with kind Constraint to the left of (=>):
      even if that type is a type synonym, type variable, indexed type or so on.
      The following (somewhat related) changes are also made:
       1. We now box equality evidence. This is required because we want
          to give (Int ~ a) the *lifted* kind Constraint
       2. For similar reasons, implicit parameters can now only be of
          a lifted kind. (?x::Int#) => ty is now ruled out
       3. Implicit parameter constraints are now allowed in superclasses
          and instance contexts (this just falls out as OK with the new
          constraint solver)
      Internally the following major changes were made:
       1. There is now no PredTy in the Type data type. Instead
          GHC checks the kind of a type to figure out if it is a predicate
       2. There is now no AClass TyThing: we represent classes as TyThings
          just as a ATyCon (classes had TyCons anyway)
       3. What used to be (~) is now pretty-printed as (~#). The box
          constructor EqBox :: (a ~# b) -> (a ~ b)
       4. The type LCoercion is used internally in the constraint solver
          and type checker to represent coercions with free variables
          of type (a ~ b) rather than (a ~# b)
  32. 24 Aug, 2011 1 commit
  33. 20 May, 2011 1 commit
  34. 24 Apr, 2011 1 commit
  35. 14 Apr, 2011 1 commit